From 3eef9993af9dc04f5e9d489e3234e5b4060ff893 Mon Sep 17 00:00:00 2001
From: Brian Anderson <banderson@mozilla.com>
Date: Tue, 2 Aug 2011 15:25:06 -0700
Subject: [PATCH] Don't pp extra lines after block open when preserving
 whitespace. Closes #759

---
 src/comp/syntax/print/pprust.rs                  | 16 +++++++++++++++-
 src/test/bench/shootout-fibo.rs                  |  1 -
 src/test/bench/shootout-nbody.rs                 |  1 -
 src/test/bench/task-perf-word-count.rs           |  1 -
 src/test/pretty/empty-lines.rs                   |  7 +++++++
 src/test/run-pass/hashmap-memory.rs              |  1 -
 src/test/run-pass/interior-vec.rs                |  1 +
 src/test/run-pass/issue-687.rs                   |  1 -
 .../run-pass/pattern-bound-var-in-for-each.rs    |  1 -
 src/test/run-pass/while-prelude-drop.rs          |  1 -
 10 files changed, 23 insertions(+), 8 deletions(-)
 create mode 100644 src/test/pretty/empty-lines.rs

diff --git a/src/comp/syntax/print/pprust.rs b/src/comp/syntax/print/pprust.rs
index 7533eced7cfa..11e13d6ebe02 100644
--- a/src/comp/syntax/print/pprust.rs
+++ b/src/comp/syntax/print/pprust.rs
@@ -172,6 +172,20 @@ fn bclose_(s: &ps, span: codemap::span, indented: uint) {
 }
 fn bclose(s: &ps, span: codemap::span) { bclose_(s, span, indent_unit); }
 
+fn is_begin(s: &ps) -> bool {
+    alt s.s.last_token() {
+      pp::BEGIN(_) { true }
+      _ { false }
+    }
+}
+
+fn is_end(s: &ps) -> bool {
+    alt s.s.last_token() {
+      pp::END. { true }
+      _ { false }
+    }
+}
+
 fn is_bol(s: &ps) -> bool {
     ret s.s.last_token() == pp::EOF ||
         s.s.last_token() == pp::hardbreak_tok();
@@ -1403,7 +1417,7 @@ fn print_comment(s: &ps, cmnt: lexer::cmnt) {
       }
       lexer::blank_line. {
         // We need to do at least one, possibly two hardbreaks.
-        pprust::hardbreak_if_not_bol(s);
+        if is_begin(s) || is_end(s) { hardbreak(s.s) }
         hardbreak(s.s);
       }
     }
diff --git a/src/test/bench/shootout-fibo.rs b/src/test/bench/shootout-fibo.rs
index 28cf4d9b9c61..f0a2009b2132 100644
--- a/src/test/bench/shootout-fibo.rs
+++ b/src/test/bench/shootout-fibo.rs
@@ -1,4 +1,3 @@
-// xfail-pretty
 
 
 // -*- rust -*-
diff --git a/src/test/bench/shootout-nbody.rs b/src/test/bench/shootout-nbody.rs
index fedab232e58c..08ef4995ad4e 100644
--- a/src/test/bench/shootout-nbody.rs
+++ b/src/test/bench/shootout-nbody.rs
@@ -1,4 +1,3 @@
-// xfail-pretty
 // based on:
 // http://shootout.alioth.debian.org/u32/benchmark.php?test=nbody&lang=java
 
diff --git a/src/test/bench/task-perf-word-count.rs b/src/test/bench/task-perf-word-count.rs
index 97fea953e3d0..0a6b94c7f2ed 100644
--- a/src/test/bench/task-perf-word-count.rs
+++ b/src/test/bench/task-perf-word-count.rs
@@ -1,4 +1,3 @@
-// xfail-pretty
 /**
    A parallel word-frequency counting program.
 
diff --git a/src/test/pretty/empty-lines.rs b/src/test/pretty/empty-lines.rs
new file mode 100644
index 000000000000..87de5ff64c27
--- /dev/null
+++ b/src/test/pretty/empty-lines.rs
@@ -0,0 +1,7 @@
+// Issue #759
+// Whitespace under block opening should not expand forever
+
+fn a() -> uint {
+
+    1u
+}
\ No newline at end of file
diff --git a/src/test/run-pass/hashmap-memory.rs b/src/test/run-pass/hashmap-memory.rs
index d60f45f2da85..6470f4d4206b 100644
--- a/src/test/run-pass/hashmap-memory.rs
+++ b/src/test/run-pass/hashmap-memory.rs
@@ -1,4 +1,3 @@
-// xfail-pretty
 /**
    A somewhat reduced test case to expose some Valgrind issues.
 
diff --git a/src/test/run-pass/interior-vec.rs b/src/test/run-pass/interior-vec.rs
index 4799a04fa8ee..254a4e51b6bb 100644
--- a/src/test/run-pass/interior-vec.rs
+++ b/src/test/run-pass/interior-vec.rs
@@ -1,4 +1,5 @@
 // xfail-stage0
+// xfail-pretty
 
 import rusti::ivec_len;
 
diff --git a/src/test/run-pass/issue-687.rs b/src/test/run-pass/issue-687.rs
index b97f9890e81f..1a0e93874f1a 100644
--- a/src/test/run-pass/issue-687.rs
+++ b/src/test/run-pass/issue-687.rs
@@ -1,5 +1,4 @@
 // xfail-stage0
-// xfail-pretty
 
 use std;
 import std::ivec;
diff --git a/src/test/run-pass/pattern-bound-var-in-for-each.rs b/src/test/run-pass/pattern-bound-var-in-for-each.rs
index 51964c34155d..504aea1d4407 100644
--- a/src/test/run-pass/pattern-bound-var-in-for-each.rs
+++ b/src/test/run-pass/pattern-bound-var-in-for-each.rs
@@ -1,5 +1,4 @@
 // xfail-stage0
-// xfail-pretty
 // Tests that trans_path checks whether a
 // pattern-bound var is an upvar (when translating
 // the for-each body)
diff --git a/src/test/run-pass/while-prelude-drop.rs b/src/test/run-pass/while-prelude-drop.rs
index e480db6d1066..badd2ae10bf8 100644
--- a/src/test/run-pass/while-prelude-drop.rs
+++ b/src/test/run-pass/while-prelude-drop.rs
@@ -1,4 +1,3 @@
-// xfail-pretty
 
 tag t { a; b(str); }